权限拒绝：android.permission.READ_EXTERNAL_STORAGE

Question

我在我的应用程序中使用 MediaStore 类并面临以下错误（logcat），

E/DatabaseUtils: Writing exception to parcel
java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=5769, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()
at android.content.ContentProvider.enforceReadPermissionInner(ContentProvider.java:539)
at android.content.ContentProvider$Transport.enforceReadPermission(ContentProvider.java:452)
at android.content.ContentProvider$Transport.query(ContentProvider.java:205)
at android.content.ContentProviderNative.onTransact(ContentProviderNative.java:112)
at android.os.Binder.execTransact(Binder.java:446)
05-11 17:27:35.982 5769-5769/com.media.wanware.fragmentdemo D/AndroidRuntime: Shutting down VM
05-11 17:27:35.984 5769-5769/com.media.wanware.fragmentdemo E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.media.wanware.fragmentdemo, PID: 5769
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.media.wanware.fragmentdemo/com.media.wanware.fragmentdemo.MainActivity}: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=5769, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2325)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387)
   at android.app.ActivityThread.access$800(ActivityThread.java:151)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:135)
   at android.app.ActivityThread.main(ActivityThread.java:5254)
   at java.lang.reflect.Method.invoke(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:372)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.SecurityException: Permission Denial: reading com.android.providers.media.MediaProvider uri content://media/external/audio/media from pid=5769, uid=10059 requires android.permission.READ_EXTERNAL_STORAGE, or grantUriPermission()
   at android.os.Parcel.readException(Parcel.java:1546)
   at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:185)
   at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:137)
   at android.content.ContentProviderProxy.query(ContentProviderNative.java:421)
   at android.content.ContentResolver.query(ContentResolver.java:478)
   at android.content.ContentResolver.query(ContentResolver.java:422)
   at com.media.wanware.fragmentdemo.MainActivity.getAllSongsFromDevice(MainActivity.java:45)
   at com.media.wanware.fragmentdemo.MainActivity.onCreate(MainActivity.java:29)
   at android.app.Activity.performCreate(Activity.java:5990)
   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2278)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2387) 
   at android.app.ActivityThread.access$800(ActivityThread.java:151) 
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1303) 
   at android.os.Handler.dispatchMessage(Handler.java:102) 
   at android.os.Looper.loop(Looper.java:135) 
   at android.app.ActivityThread.main(ActivityThread.java:5254) 
   at java.lang.reflect.Method.invoke(Native Method) 
   at java.lang.reflect.Method.invoke(Method.java:372) 
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

我读过这个问题，

Android reading external storage gives securityException

但我已在下面的清单中正确放置了权限，

Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.media.wanware.fragmentdemo">

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="19" />

    <uses-permission
        android:name="android.permission.READ_EXTERNAL_STORAGE"
        android:maxSdkVersion="19" />

    <uses-permission
        android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        android:maxSdkVersion="19" />

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">




        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

此外，在进一步阅读后，我也经历了以下问题，

Android permission doesn't work even if I have declared it

如今未获得您的许可的主要原因是 您的项目的 targetSdkVersion 为 23 或更高

对于这些权限，不仅您的 targetSdkVersion 23+ 应用 需要有元素，但你也必须 在运行时向 Android 6.0+ 上的用户请求这些权限 设备，使用 checkSelfPermission() 和 requestPermissions().

作为临时解决方法，将 targetSdkVersion 降到 23 以下。

但我的目标 SDK 仅低于 23。 为什么我会遇到同样的错误？

Answer 1

SDK 23 具有处理 Android 权限的所有新方法和功能，可以尝试使用较低的 SDK 版本编译您的代码。这可能会解决您的问题。

并从您的权限中删除maxSdkVersion。

快乐编码:)

Answer 2

比用低版本编译要好，你必须为所有版本编写适当的代码，否则你最终会被当前的编程方式所遗忘，尤其是在 android 中。

查看这篇文章，了解如何在运行时请求权限here。

以下是我如何正确请求这些权限的示例：

if (ActivityCompat.checkSelfPermission(context, android.Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {

            // Should we show an explanation?

            if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context,
                    android.Manifest.permission.READ_EXTERNAL_STORAGE)) {

                Snackbar.make(getWindow().getDecorView().getRootView(), "We need permissions to do stuff.\n Please allow.", Snackbar.LENGTH_LONG)
                        .setAction("Settings", new View.OnClickListener() {
                            @Override
                            public void onClick(View view) {
                                final Intent i = new Intent();
                                i.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                                i.addCategory(Intent.CATEGORY_DEFAULT);
                                i.setData(Uri.parse("package:" + context.getPackageName()));
                                i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                i.addFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);
                                i.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
                                context.startActivity(i);
                            }
                        }).show();

                ActivityCompat.requestPermissions((Activity) context,
                        new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.ACCESS_COARSE_LOCATION},
                        MY_PERMISSIONS_REQUEST_READ);

            } else {

                ActivityCompat.requestPermissions((Activity) context,
                        new String[]{android.Manifest.permission.ACCESS_FINE_LOCATION, android.Manifest.permission.ACCESS_COARSE_LOCATION},
                        MY_PERMISSIONS_REQUEST_READ);

            }

        }else {
            //Do your stuff here 
        }